It is often the case that it is desirable to take images of a surface feature under repeatable conditions. This is particularly true in applications where it is desirable to track any change in the surface feature. Currently there is no means for providing good quality moderately magnified images whose physical and optical variables are optimized and integrated in a field setting.
One application where such an imaging system would be desirable is in dermatological diagnosis of dysplastic nevi. Dysplastic nevus syndrome is a medical condition appropriate to select skin types who have a low tolerance to sunlight and a higher risk of skin cancer than the general population. Among other physical traits, an individual with dysplastic nevus syndrome typically develops a number of skin lesions (nevi), each of which may become unstable over time and must be carefully watched for signs of malignancy. These nevi typically appear on the upper body. Treatment typically requires tracking each nevus in order to determine if that nevus is undergoing physical changes in size, shape or color and may need to be excised Excision of all nevi of a patient is generally not performed, because of their great number and the increased risks associated with repeated surgeries.
In the current art, the dermatologist relies upon visual inspection of each nevus. This requires the dermatologist to remember the last state of each nevus, a difficult task due to their number, in order to detect any changes in state. Alternatively, the dermatologist could prepare a written summary of the state of each nevus or at least those of most concern. This summary would permit review of the prior state of the nevus. Such summaries are necessarily poor substitutes for review of the prior status of the nevus. It is also feasible to take ordinary photographs of the skin for later comparison. This technique is unsatisfactory because the physical conditions for taking such photographs cannot be easily repeated. This means that the photographs cannot be relied upon to clearly indicate change in the skin condition rather than change in the lighting, angle or the like when the photograph was exposed.
There are other fields where repeatable images of surface features would be helpful Quality control of industrial finishing, such as painting, would also benefit from the capability of such measurements. The results of changes in the parameters of the finishing operation could be more readily determined if images of the finished products could be compared without worry that change conditions of measurement create inconsequential differences.
It is therefore a need in the art to be able to form images of surfaces under reliably repeatable conditions in the field whose physical and optical variables have been optimized and of suitable repeatability for submission to, and analysis by, a computer.